1. Field of Invention
Embodiments of the invention relate, in general, to cable networks. More specifically, embodiments of the invention relate to methods and systems for detecting a cloned cable modem in a cable network.
2. Description of the Background Art
A cable network is a programming service, which includes a number of cable modems. The cable modems operate according to an international standard known as Data Over Cable Service Interface Specification (DOCSIS). A cable modem termination system (CMTS) and the cable modems together constitute the primary components of the DOCSIS. In a DOCSIS-based cable network, each cable modem has a specific Medium Access Control (MAC) address, which is globally unique. Each cable modem is configured in the cable network according to the MAC address.
A cable modem has to complete steps as specified in the Baseline Privacy Interface Plus (BPI+) security negotiation process. The cable modem may be further authenticated by proving private key certificates, stored in the cable modem, valid via cryptographic key exchange. Moreover, the CMTS inserts a cryptographic signature in a Message Integrity Check (MIC) field. The MIC allows a one-time registration of the cable modem. The MIC matches the cryptographic signature and allows registration of the cable modem. This feature is known as cable dynamic-secret, which is also known as DMIC. The purpose of DMIC is to ensure that if a cable modem with a MAC address “M” tries to access the network, must only utilize parameters assigned by provisioning to the cable modem whose MAC address is “M. Therefore, the DMIC protects against re-registration of the cable modem with the same cryptographic signature.